Is the audio DIY QR code presented in a letter of a lifetime all a QR code sticker? . Or some postcards randomly printed in the whole set of postcards?
Yes, some QR code stickers can only be used once. . . Buying four or five postcards in a bag is basically giving them away. There are 4 or 5 postcards in a bag, but there are almost no postcards in a box of13,4. . . Unless you buy a life-long library series, to be honest, I don't think it's useful. I have a lot there. Do you need them?